Image pickup device and electronic system including the same

ABSTRACT

An image pickup device includes first and second cameras, and first and second image signal processors (ISP). The first camera obtains a first image of an object. The second camera obtains a second image of the object. The first ISP performs a first auto focusing (AF), a first auto white balancing (AWB) and a first auto exposing (AE) for the first camera based on a first region-of-interest (ROI) in the first image, and obtains a first distance between the object and the first camera based on a result of the first AF. The second ISP calculates first disparity information associated with the first and second images based on the first distance, moves a second ROI in the second image based on the first disparity information, and performs a second AF, a second AWB and a second AE for the second camera based on the moved second ROI.

CROSS-REFERENCE TO RELATED APPLICATION

This is a Continuation of U.S. application Ser. No. 16/677,718, filedNov. 8, 2019, which issued as U.S. Pat. No. 11,122,186, on Sep. 14,2021, which is a Continuation of U.S. application Ser. No. 16/411,222,filed May 14, 2019, which issued as U.S. Pat. No. 10,511,746, on Dec.17, 2019, which is a Continuation of U.S. application Ser. No.15/658,479, filed Jul. 25, 2017, which issued as U.S. Pat. No.10,321,021, on Jun. 11, 2019, and in which a claim for priority under 35U.S.C. § 119 is made to Korean Patent Application No. 10-2016-0095081,filed on Jul. 26, 2016 in the Korean Intellectual Property Office(KIPO), the disclosure of which is incorporated herein in its entiretyby reference.

BACKGROUND

The inventive concepts described herein relate generally to image pickupand processing, and more particularly to image pickup devices andelectronic systems including the image pickup devices.

Image recording devices (e.g., cameras) have been adopted in variouselectronic systems and mobile systems such as, for example, computers,mobile phones, tablets, virtual reality (VR) equipment, and roboticsystems. Recently, research has focused on dual camera systems includingtwo cameras, and/or multi-camera systems including more than threecameras. Research has further focused on techniques for preventingdeterioration of the quality of images obtained by systems including aplurality of cameras.

SUMMARY

Embodiments of the inventive concept are provided to substantiallyobviate one or more problems due to limitations and disadvantages of therelated art.

Embodiments of the inventive concept provide an image pickup devicecapable of efficiently synchronizing a plurality of cameras with eachother.

Embodiments of the inventive concept further provide an electronicsystem including the image pickup device.

Embodiments of the inventive concept provide an image pickup deviceincluding a first camera, a second camera, a first image signalprocessor (ISP) and a second ISP. The first camera is configured toobtain a first image of an object. The second camera is configured toobtain a second image of the object. The first ISP is configured toperform a first auto focusing (AF), a first auto white balancing (AWB)and a first auto exposing (AE) for the first camera based on a firstregion-of-interest (ROI) in the first image, and configured to obtain afirst distance between the object and the first camera based on a resultof the first AF. The second ISP is configured to determine firstdisparity information associated with the first and second images basedon the first distance, configured to move a second ROI in the secondimage based on the first disparity information, and configured toperform a second AF, a second AWB and a second AE for the second camerabased on the moved second ROI.

Embodiments of the inventive concept further provide an electronicsystem including a processor and an image pickup device controlled bythe processor. The image pickup device includes a first camera, a secondcamera, a first image signal processor (ISP) and a second ISP. The firstcamera is configured to obtain a first image of an object. The secondcamera is configured to obtain a second image of the object. The firstISP is configured to perform a first auto focusing (AF), a first autowhite balancing (AWB) and a first auto exposing (AE) for the firstcamera based on a first region-of-interest (ROI) in the first image, andconfigured to obtain a first distance between the object and the firstcamera based on a result of the first AF. The second ISP is configuredto determine first disparity information associated with the first andsecond images based on the first distance, configured to move a secondROI in the second image based on the first disparity information, and isconfigured to perform a second AF, a second AWB and a second AE for thesecond camera based on the moved second ROI.

Embodiments of the inventive concept still further provide an imagepickup device including a plurality of first and second through nthcameras respectively configured to obtain first and second through nthimages of an object; and a plurality of first and second through nthimage signal processors (ISPs) respectively associated with the firstand second through nth cameras, wherein n is an integer greater than 2.The first ISP is configured to perform a first auto focusing (AF), afirst auto white balancing (AWB) and a first auto exposing (AE) for thefirst camera based on a first region-of-interest (ROI) in the firstimage and to obtain a first distance between the first camera and theobject. The second through nth ISPs are configured to respectively movesecond through nth ROIs of the second through nth images based on thefirst distance, and to respectively perform AF, AWB and AE for thesecond through nth cameras based on the moved second through nth ROIs.

In the image pickup device according to embodiments of the inventiveconcept, AF, AWB and AE for a master camera may be performed based onROI, and AFs, AWBs and AEs for slave cameras may be performed based onROIs that are moved by results of the AF, AWB and AE for the mastercamera, and thus the AFs, AWBs and AEs for all cameras may beefficiently synchronized with each other based on the result of the AF,AWB and AE for the master camera. Accordingly, when a plurality ofimages obtained by a plurality of cameras in the image pickup device arecombined, an image quality of a composite image may not be degraded.

BRIEF DESCRIPTION OF THE DRAWINGS

Illustrative, non-limiting example embodiments will be more clearlyunderstood from the following detailed description taken in conjunctionwith the accompanying drawings.

FIG. 1 illustrates a block diagram of an image pickup device accordingto embodiments of the inventive concept.

FIG. 2 illustrates a block diagram of cameras and image signalprocessors included in the image pickup device of FIG. 1 .

FIG. 3 illustrates a diagram describing an arrangement of camerasaccording to embodiments of the inventive concept.

FIG. 4 illustrates a concept of disparity in an image pickup devicehaving an arrangement of cameras such as in FIG. 3 .

FIG. 5 illustrates a diagram for describing an example of moving aregion-of-interest in the image pickup device according to an embodimentof the inventive concept.

FIG. 6 illustrates another diagram for explaining the example of movinga region-of-interest according to FIG. 5 .

FIG. 7 illustrates another diagram for explaining the example of movinga region-of-interest according to FIG. 5 .

FIG. 8 illustrates a diagram for describing another example of moving aregion-of-interest in the image pickup device according to an embodimentof the inventive concept.

FIG. 9 illustrates a diagram for explaining the another example ofmoving a region-of-interest according to FIG. 8 .

FIG. 10 illustrates a diagram for describing an example of auto focusingin the image pickup device according to an embodiment of the inventiveconcept.

FIG. 11 illustrates a diagram for describing an example of auto whitebalancing in the image pickup device according to an embodiment of theinventive concept.

FIG. 12 illustrates a diagram for describing an example of auto exposingin the image pickup device according to an embodiment of the inventiveconcept.

FIG. 13 illustrates a block diagram of an image pickup device accordingto an embodiment of the inventive concept.

FIG. 14 illustrates a flow chart of a method of operating an imagepickup device according to an embodiment of the inventive concept.

FIG. 15 illustrates a flow chart of an example of step S100 in FIG. 14 .

FIG. 16 illustrates a flow chart of an example of step S500 in FIG. 14 .

FIG. 17 illustrates a block diagram of an electronic system according toan embodiment of the inventive concept.

DETAILED DESCRIPTION

Various example embodiments will be described more fully with referenceto the accompanying drawings, in which embodiments are shown. Thepresent disclosure may, however, be embodied in many different forms andshould not be construed as limited to the embodiments set forth herein.Like reference numerals refer to like elements throughout thisapplication.

As is traditional in the field of the inventive concepts, embodimentsmay be described and illustrated in terms of blocks which carry out adescribed function or functions. These blocks, which may be referred toherein as units or modules or the like, are physically implemented byanalog and/or digital circuits such as logic gates, integrated circuits,microprocessors, microcontrollers, memory circuits, passive electroniccomponents, active electronic components, optical components, hardwiredcircuits and the like, and may optionally be driven by firmware and/orsoftware. The circuits may, for example, be embodied in one or moresemiconductor chips, or on substrate supports such as printed circuitboards and the like. The circuits constituting a block may beimplemented by dedicated hardware, or by a processor (e.g., one or moreprogrammed microprocessors and associated circuitry), or by acombination of dedicated hardware to perform some functions of the blockand a processor to perform other functions of the block. Each block ofthe embodiments may be physically separated into two or more interactingand discrete blocks without departing from the scope of the inventiveconcepts. Likewise, the blocks of the embodiments may be physicallycombined into more complex blocks without departing from the scope ofthe inventive concepts.

FIG. 1 illustrates a block diagram of an image pickup device accordingto an embodiment of the inventive concept.

Referring to FIG. 1 , an image pickup device 100 includes a first camera(CAMERA1) 200 a, a second camera (CAMERA2) 200 b, a first image signalprocessor (ISP1) 300 a and a second image signal processor (ISP2) 300 b.The first image signal processor 300 a and the second image signalprocessor 300 b may hereinafter be referred to as ISPs. Each of the ISPs300 a and 300 b in the image pickup device 100 may control a respectiveone of the cameras 200 a and 200 b in the image pickup device 100. Inother words, in the image pickup device 100, the number of the ISPs maybe substantially the same as the number of the cameras.

The first camera 200 a obtains a first image of an object 10, and thesecond camera 200 b obtains a second image of the object 10. The secondcamera 200 b may be disposed or arranged adjacent to the first camera200 a. A position and a viewpoint of the second camera 200 b may bedifferent from a position and a viewpoint of the first camera 200 a, andthus disparity or parallax between the first and second images mayexist, as will be described with reference to FIGS. 3 and 4 .

In some embodiments of the inventive concept, the first camera 200 a maybe set as a master camera and the second camera 200 b may be set as aslave camera, based on a user setting signal and/or an internalparameter.

The first ISP 300 a performs a first auto focusing (or auto focus (AF)),a first auto white balancing (or auto white (color) balance (AWB)) and afirst auto exposing (or auto exposure (AE)) for the first camera 200 abased on a first region-of-interest (ROI) in the first image. The AF,AWB and AE as performed may collectively be referred to as performing athree-automation (3A).

The second ISP 300 b performs a second AF, a second AWB and a second AEfor the second camera 200 b based on a second ROI in the second image.Before the second AF, the second AWB and the second AE are preformed, afirst distance between the object 10 and the first camera 200 a isobtained based on a result of the first AF, and first disparityinformation associated with the first and second images is calculatedbased on the first distance. For example, the first distance may beobtained by the first ISP 300 a, and the first disparity information maybe calculated by the second ISP 300 b. The second ISP 300 b moves asecond ROI in the second image based on the first disparity information,and performs the second AF, the second AWB and the second AE for thesecond camera 200 b based on the moved second ROI. Thus, the AFs, AWBs,and AEs for the first and second cameras 200 a and 200 b may besynchronized with each other. In other words, the 3A for all cameras(e.g., the first and second cameras 200 a and 200 b) may be synchronizedwith each other based on a result of the 3A for a master camera (e.g.,the first camera 200 a).

FIG. 2 illustrates a block diagram of cameras and image signalprocessors included in the image pickup device of FIG. 1 .

Referring to FIG. 2 , the first camera 200 a includes a first lens 210a, a first shutter 220 a, a first sensor 230 a, a first lens driver 240a and a first shutter driver 250 a.

The first lens 210 a may concentrate a first external light signal L1 onthe first sensor 230 a. For example, the first external light signal L1may include a visible light signal, an infrared light signal and/or anear-infrared light signal. Although the camera 200 a in FIG. 2 includesa single lens 210 a, the camera included in the image pickup device mayinclude two lenses or more than two lenses according to otherembodiments of the inventive concept.

The first sensor 230 a may obtain a first image IIMG1 based on the firstexternal light signal L1. The first image IIMG1 may be an image beforethe first AF, the first AWB and the first AE are performed. For example,the first image IIMG1 may be an unfocused image that includes blurred orincomplete image information of the object 10.

In some embodiments of the inventive concept, the first sensor 230 a mayinclude a complementary metal oxide semiconductor (CMOS) image sensor.For example, the first sensor 230 a may include an RGB sensor. In otherembodiments of the inventive concept, the first sensor 230 a may includeone of various types of image sensors, such as a charged coupled device(CCD) image sensor.

The first shutter 220 a may selectively provide the first external lightsignal L1 to the first sensor 230 a. For example, the first shutter 220a may include one of an electrical shutter, an optical shutter, amechanical shutter, or the like.

In some embodiments, the first shutter 220 a may be integrated with thefirst sensor 230 a. In other embodiments, the first shutter 220 a may beseparate from the first sensor 230 a.

The first lens driver (LENSDRIVER1) 240 a may generate a first lenscontrol signal LS1 for controlling a position of the first lens 210 abased on a first AF control signal AFC1. For example, the first lensdriver 240 a may include one of various types of motors, such as a voicecoil motor (VCM). The first shutter driver (SHUTTER DRIVER1) 250 a maygenerate a first shutter control signal SS1 for controlling a switchingtime of the first shutter 220 a (e.g., a time point of opening orclosing a shutter) and/or an exposure time of the first shutter 220 a(e.g., an integration period of a shutter) based on a first AE controlsignal AEC1.

The first ISP 300 a includes a first AF controller (AF CONTROLLER1) 310a, a first AE controller (AE CONTROLLER1) 320 a, a first AWB controller(AWB CONTROLLER1) 330 a, a first ROI determinator (ROI DETERMINATOR1)340 a and a first image compensator 350 a.

The first ROI determinator 340 a may set the first ROI in the firstimage IIMG1. It is well known that certain spatial and temporal regionsor objects in pictures are of more interest/importance to a user thanother areas. For example, in video conferencing applications, the viewermay pay more attention to face regions when compared to other regions.In security applications, areas of potential activity (e.g., doors,windows, etc.) may be more important. These more important regions orthe regions where the viewer pays more attention to may be referred toas ROIs. The ROI may be referred to as a statistics region.

In some embodiments of the inventive concept, the first ROI may bemanually set based on a user's operation. In other embodiments, thefirst ROI may be automatically set based on predetermined rules orcriterions.

In some embodiments, the first ROI may include a first focus ROI forperforming the first AF, a first white balance ROI for performing thefirst AWB, and a first exposure ROI for performing the first AE. In thefirst image IIMG1, locations and shapes of the first focus ROI, thefirst white balance ROI and the first exposure ROI may be substantiallythe same as or different from each other according to embodiments of theinventive concept. The first ROI determinator 340 a may generate firstfocus ROI information AFR1 associated with the first focus ROI, firstwhite balance ROI information AWBR1 associated with the first whitebalance ROI, and first exposure ROI information AER1 associated with thefirst exposure ROI.

The first AF controller 310 a may generate the first AF control signalAFC1 for the first AF based on the first focus ROI information AFR1. Theposition of the first lens 210 a may be adjusted based on the first AFcontrol signal AFC1 (e.g., based on the first lens control signal LS1generated using the first AF control signal AFC1). In some embodimentsof the inventive concept, the first AF may be performed based on anactive scheme which measures a distance to a subject independently of anoptical system, and subsequently adjusts the optical system for correctfocus. In other embodiments, the first AF may be performed based on apassive scheme which determines correct focus by performing a passiveanalysis of an image that is entering the optical system. In still otherembodiments, the first AF may be performed based on a hybrid schemewhich performs both the active scheme and the passive scheme.

The first AE controller 320 a may generate the first AE control signalAEC1 for the first AE based on the first exposure ROI information AER1.The operation of the first shutter 220 a may be adjusted based on thefirst AE control signal AEC1 (e.g., based on the first shutter controlsignal SS1 generated using the first AE control signal AEC1). Forexample, as will be described with reference to FIG. 12 , the first AEmay be performed based on an exposure index (EI).

The first AWB controller 330 a may generate a first AWB control signalAWBC1 for the first AWB based on the first white balance ROI informationAWBR1. For example, as will be described with reference to FIG. 11 , thefirst AWB may be performed based on a correlated color temperature(CCT).

The first image compensator 350 a includes a first processing block(PROCESSING BLOCK11) 352 a, a second processing block (PROCESSINGBLOCK12) 354 a and a third processing block 356 a (PROCESSING BLOCK13)that perform image compensations and/or corrections. The firstprocessing block 352 a may perform de-mosaicing, de-noising and/orsharpening on an image input to the first processing block 352 a. Thesecond processing block 354 a may perform the first AWB on an imageoutput from the first processing block 352 a based on the first AWBcontrol signal AWBC1. The third processing block 356 a may perform colorcorrection, color conversion and/or gamma correction on an image outputfrom the second processing block 354 a.

The first image compensator 350 a may compensate the first image IIMG1,or may compensate a first output image OIMG1 to generate a firstcompensation image OIMG1′. The first output image OIMG1 may be an imagethat is obtained by the first camera 200 a after the first AF, the firstAWB and the first AE are completed. For example, the first output imageOIMG1 may be a focused image that includes clear, distinct, vivid orcomplete image information of the object 10.

The first ISP 300 a may provide results of the first AF, the first AWBand the first AE to the second ISP 300 b. For example, the first AFcontroller 310 a may obtain a first position P1 (e.g., a finallyadjusted position) of the first lens 210 a and a first distance Zbetween the object 10 and the first camera 200 a based on a result ofthe first AF. The first AWB controller 330 a may convert a result of thefirst AWB into a first CCT CCT1. The first AE controller 320 a mayconvert a result of the first AE into a first EI EI1 and may obtain afirst exposure time IT1 of the first shutter 220 a based on the firstAE. The first ROI determinator 340 a may generate first ROI informationROI1 including the first focus ROI information AFR1, the first whitebalance ROI information AWBR1 and the first exposure ROI informationAER1. The first distance Z, the first ROI information ROI1, the firstposition P1, the first CCT CCT1, the first EI EI1 and the first exposuretime IT1 may be provided from the first ISP 300 a to the second ISP 300b.

In some embodiments of the inventive concept, the first AF, the firstAWB and the first AE may be substantially simultaneously or concurrentlyperformed. In other embodiments, the first AF may be performed, and thenthe first AWB and the first AE may be performed after the first AF iscompleted.

The second camera 200 b includes a second lens 210 b, a second shutter220 b, a second sensor 230 b, a second lens driver (LENS DRIVER2) 240 band a second shutter driver (SHUTTER DRIVER2) 250 b. Each elementincluded in the second camera 200 b may be similar to or substantiallythe same as a respective element included in the first camera 200 a. Forexample, the second lens 210 b may concentrate a second external lightsignal L2 on the second sensor 230 b. The second sensor 230 b may obtaina second image IIMG2 based on the second external light signal L2. Thesecond image IIMG2 may be an image before the second AF, the second AWBand the second AE are performed. The second shutter 220 b mayselectively provide the second external light signal L2 to the secondsensor 230 b. The second lens driver 240 b may generate a second lenscontrol signal LS2 for controlling a position of the second lens 210 bbased on a second AF control signal AFC2. The second shutter driver 250b may generate a second shutter control signal SS2 for controlling aswitching time of the second shutter 220 b and/or an exposure time ofthe second shutter 220 b based on a second AE control signal AEC2.

The second ISP 300 b includes a second AF controller (AF CONTROLLER2)310 b, a second AE controller (AE CONTROLLER2) 320 b, a second AWBcontroller (AWB CONTROLLER2) 330 b, a second ROI determinator (ROIDETERMINATOR2) 340 b and a second image compensator 350 b. Each elementincluded in the second ISP 300 b may be similar to or substantially thesame as a respective element included in the first ISP 300 a.

The second ROI determinator 340 b may set the second ROI in the secondimage IIMG2, may calculate the first disparity information associatedwith the first and second images IIMG1 and IIMG2 based on the firstdistance Z, and may move the second ROI in the second image IIMG2 basedon the first disparity information. For example, the second ROI in thesecond image IIMG2 may have an initial location that is substantiallythe same as the location of the first ROI in the first image IIMG1. Forexample, the second ROI may be shifted in the second image IIMG2 by afirst disparity vector included in the first disparity information.

Similarly to the first ROI, the second ROI may include a second focusROI for performing the second AF, a second white balance ROI forperforming the second AWB, and a second exposure ROI for performing thesecond AE. The second ROI determinator 340 b may move the second focusROI, the second white balance ROI and the second exposure ROI based onthe first disparity information. The second ROI determinator 340 b maygenerate second focus ROI information AFR2 associated with the movedsecond focus ROI, second white balance ROI information AWBR2 associatedwith the moved second white balance ROI, and second exposure ROIinformation AER2 associated with the moved second exposure ROI.

The second AF controller 310 b may generate the second AF control signalAFC2 for the second AF based on the second focus ROI information AFR2and the first position P1 of the first lens 210 a. The position of thesecond lens 210 b may be adjusted based on the second AF control signalAFC2 (e.g., based on the second lens control signal LS2 generated usingthe second AF control signal AFC2). For example, as will be describedwith reference to FIG. 10 , a position of the second lens 210 b afterthe second AF (e.g., a finally adjusted position or a second position)may be within a predetermined range with respect to the first positionP1.

The second AE controller 320 b may generate the second AE control signalAEC2 for the second AE based on the second exposure ROI information AER2and the first EI EI1. The operation of the second shutter 220 b may beadjusted based on the second AE control signal AEC2 (e.g., based on thesecond shutter control signal SS2 generated using the second AE controlsignal AEC2). For example, as will be described with reference to FIG.12 , a second EI corresponding to a result of the second AE may bewithin a predetermined range with respect to the first EI EI1.

The second AWB controller 330 b may generate a second AWB control signalAWBC2 for the second AWB based on the second white balance ROIinformation AWBR2 and the first CCT CCT1. For example, as will bedescribed with reference to FIG. 11 , a second CCT corresponding to aresult of the second AWB may be within a predetermined range withrespect to the first CCT CCT1.

The second image compensator 350 b includes a fourth processing block(PROCESSING BLOCK21) 352 b, a fifth processing block (PROCESSINGBLOCK22) 354 b and a sixth processing block (PROCESSING BLOCK23) 356 bthat perform image compensations and/or corrections. The fourthprocessing block 352 b may perform de-mosaicing, de-noising and/orsharpening on an image input to the fourth processing block 352 b. Thefifth processing block 354 b may perform the second AWB on an imageoutput from the fourth processing block 352 b based on the second AWBcontrol signal AWBC2. The sixth processing block 356 b may perform colorcorrection, color conversion and/or gamma correction on an image outputfrom the fifth processing block 354 b. The second image compensator 350b may compensate the second image IIMG2, or may compensate a secondoutput image OIMG2 to generate a second compensation image OIMG2′. Thesecond output image OIMG2 may be an image that is obtained by the secondcamera 200 b after the second AF, the second AWB and the second AE arecompleted.

The second AF, the second AWB and the second AE may be performed afterthe first AF, the first AWB and the first AE are completed. In someembodiments of the inventive concept, the second AF, the second AWB andthe second AE may be substantially simultaneously or concurrentlyperformed. In other embodiments, the second AF may be performed, andthen the second AWB and the second AE may be performed after the secondAF is completed.

Although not illustrated in FIG. 2 , each of the ISPs 300 a and 300 bmay further include a storage block that stores information (e.g., thefirst distance Z, the first ROI information ROI1, the first position P1,the first CCT CCT1, the first EI EI1, the first exposure time IT1, thesecond ROI information, the second position, the second CCT, the secondEI, etc.) and/or a lookup table that will be described with reference toFIGS. 10 and 12 . For example, the storage block may include at leastone volatile memory and/or at least one nonvolatile memory.

FIG. 3 illustrates a diagram describing an arrangement of camerasaccording to embodiments of the inventive concept. FIG. 4 illustrates aconcept of disparity in an image pickup device having an arrangement ofcameras such as in FIG. 3 .

Referring to FIGS. 3 and 4 , the first camera 200 a and the secondcamera 200 b may photograph an identical scene from different points ofview. In FIG. 3 , the scene may include a first object 10 and a secondobject 20. The first object 10 may be a main object or a foreground thatis to be captured (e.g., interested by a user), and the second object 20may be a subsidiary object or a background.

In some embodiments of the inventive concept, the first camera 200 a andthe second camera 200 b may be arranged in parallel with each other in afirst direction DR1. For example, in FIG. 3 , the first camera 200 a maybe disposed on the relative left side, and the second camera 200 b maybe disposed on the relative right side.

A first image IIMGA in FIG. 4 may be photographed by the first camera200 a, and a second image IIMGB in FIG. 4 may be photographed by thesecond camera 200 b.

Since the first image IIMGA and the second image IIMGB are obtained byphotographing the identical scene, the first image IIMGA and the secondimage IIMGB may include identical components. For example, the firstobject 10 in FIG. 3 may correspond to an object 11 in the first imageIIMGA in FIG. 4 and an object 12 in the second image IIMGB in FIG. 4 .The second object 20 in FIG. 3 may correspond to an object 21 in thefirst image IIMGA in FIG. 4 and an object 22 in the second image IIMGBin FIG. 4 .

Since the first camera 200 a and the second camera 200 b have differentpoints of view, the first image IIMGA and the second image IIMGB mayinclude the first object 10 and the second object 20 at differentpositions. In other words, locations of the objects 11 and 12 in thefirst and second images IIMGA and IIMGB may be different from eachother, and locations of the objects 21 and 22 in the first and secondimages IIMGA and IIMGB may be different from each other.

As described above, in the images IIMGA and IIMGB including theidentical scene, differences between the images IIMGA and IIMGB that arecaused by the different points of view of the cameras 200 a and 200 bmay be referred to as disparity or parallax (e.g., binocular disparityor disparity parallax).

FIG. 5 illustrates a diagram for describing an example of moving aregion-of-interest in the image pickup device according to embodimentsof the inventive concept. FIG. 6 illustrates another diagram forexplaining the example of moving a region-of-interest according to FIG.5 . FIG. 7 illustrates another diagram for explaining the example ofmoving a region-of-interest according to FIG. 5 .

FIGS. 5, 6 and 7 illustrate an example where an image rectification isperformed on two images IIMG11 and IIMG21 photographed respectively bythe first and second cameras 200 a and 200 b. The image rectificationmay be a transformation process used to project two-or-more images ontoa common image plane. For example, the image rectification may beperformed based on epipolar geometry. All rectified images may satisfythe following two properties: (1) all epipolar lines are parallel to thehorizontal axis; and (2) corresponding points have identical verticalcoordinates.

Referring to FIGS. 1, 5, 6 and 7 , a location of the object 10 in realworld is denoted by X, a location of the object 10 in the first imageIIMG11 obtained by the first camera 200 a (e.g., a master camera) isdenoted by x, and a location of the object 10 in the second image IIMG21obtained by the second camera 200 b (e.g., a slave camera) is denoted byx′. In FIG. 5 , an optical center of the first camera 200 a is denotedby OC, an optical center of the second camera 200 b is denoted by OC′,an effective focal length of the first camera 200 a is denoted by f, alength of a baseline is denoted by B, and the first distance between theobject 10 and the first camera 200 a is denoted by Z.

As illustrated in FIG. 6 , to perform AFs for the first and secondcameras 200 a and 200 b, a first focus ROI AFR11 in the first imageIIMG11 is set based on a location x of the object 10 in the first imageIIMG11, and then the first AF for the first camera 200 a is performedbased on the first focus ROI AFR11. A second focus ROI AFR21 in thesecond image IIMG21 has an initial location that is substantially thesame as a location of the first focus ROI AFR11 in the first imageIIMG11. The second AF for the second camera 200 b may not be performedyet based on the second focus ROI AFR21 in FIG. 6 because a location x′of the object 10 in the second image IIMG21 is different from theinitial location of the second focus ROI AFR21.

Thus, as illustrated in FIG. 7 , the second focus ROI AFR21 is moved inthe second image IIMG21 such that moved second focus ROI AFR21′corresponds to the location x′ of the object 10 in the second imageIIMG21, and then the second AF for the second camera 200 b is performedbased on the moved second focus ROI AFR21′. Accordingly, the AFs for thefirst and second cameras 200 a and 200 b may be efficiently synchronizedwith each other and may be performed with respect to the locations x andx′ of the object 10 in the images IIMG11 and IIMG21, respectively.

In some embodiments of the inventive concept, as illustrated in FIGS. 6and 7 , when the image rectification is performed on the first andsecond images IIMG11 and IIMG21, the location x′ of the object 10 in thesecond image IIMG21 may be shifted from the location x of the object 10in the first image IIMG11 in only a first direction DR1. In other words,the first disparity information, which corresponds to a differencebetween the location x of the object 10 in the first image IIMG11 andthe location x′ of the object 10 in the second image IIMG21 in FIGS. 6and 7 , may be represented as a one-dimensional (1D) disparity vectorDV1 in the rectified images IIMG11 and IIMG21. A magnitude of the 1Ddisparity vector DV1 in FIG. 7 may be obtained by Equation 1.DV1=B*f/Z  [Equation 1]

As illustrated in FIG. 7 , the moved second focus ROI AFR21′ may beobtained by moving the second focus ROI AFR21 by the 1D disparity vectorDV1.

FIG. 8 illustrates a diagram for describing another example of moving aregion-of-interest in the image pickup device according to embodimentsof the inventive concept. FIG. 9 illustrates a diagram for explainingthe another example of moving a region-of-interest according to FIG. 8 .

FIGS. 8 and 9 illustrate an example where the image rectification is notperformed on two images IIMG12 and IIMG22 respectively photographed bythe first and second cameras 200 a and 200 b.

Referring to FIGS. 1, 8 and 9 , the example of FIGS. 8 and 9 may besubstantially the same as the example of FIGS. 6 and 7 , except that theimage rectification is not performed on two images IIMG12 and IIMG22.

As illustrated in FIG. 8 , to perform AFs for the first and secondcameras 200 a and 200 b, a first focus ROI AFR12 in the first imageIIMG12 is set based on a location x of the object 10 in the first imageIIMG12, and then the first AF for the first camera 200 a is performedbased on the first focus ROI AFR12. As illustrated in FIG. 9 , tosynchronize the AFs for the first and second cameras 200 a and 200 bwith each other, a second focus ROI AFR22 is moved in the second imageIIMG22 such that moved second focus ROI AFR22′ corresponds to a locationx′ of the object 10 in the second image IIMG22, and then the second AFfor the second camera 200 b is performed based on the moved second focusROI AFR22′.

In some embodiments of the inventive concept, as illustrated in FIGS. 8and 9 , when the image rectification is not performed on the first andsecond images IIMG12 and IIMG22, the location x′ of the object 10 in thesecond image IIMG22 may be shifted from the location x of the object 10in the first image IIMG12 in both the first direction DR1 and a seconddirection DR2 crossing (e.g., substantially perpendicular to) the firstdirection DR1. In other words, the first disparity information, whichcorresponds to a difference between the location x of the object 10 inthe first image IIMG12 and the location x′ of the object 10 in thesecond image IIMG22 in FIGS. 8 and 9 , may be represented as atwo-dimensional (2D) disparity vector DV2 in the non-rectified imagesIIMG12 and IIMG22. A magnitude of the 2D disparity vector DV2 in FIG. 9may be obtained by Equations 2, 3 and 4.x=K[I|O]X  [Equation 2]x′=K′[R|t]X=K′RK ⁻¹ x+K′t/Z  [Equation 3]DV2=x−x′  [Equation 4]

In Equations 2, 3 and 4, X indicates a location of the object 10 in realworld, x indicates the location of the object 10 in the first imageIIMG12 obtained by the first camera 200 a (e.g., a master camera), andx′ indicates the location of the object 10 in the second image IIMG22obtained by the second camera 200 b (e.g., a slave camera). K indicatesan intrinsic matrix of the first camera 200 a, K′ indicates an intrinsicmatrix of the second camera 200 b, I indicates a unit matrix, and Oindicates a zero matrix. R indicates a relative rotation of the secondcamera 200 b with respect to the first camera 200 a, t indicates arelative translation of the second camera 200 b with respect to thefirst camera 200 a, and Z indicates the first distance between theobject 10 and the first camera 200 a. For example, each of K, K′, I andR may be a 3*3 matrix, and each of X, x, x′, O and t may be a 3*1matrix.

As illustrated in FIG. 9 , the moved second focus ROI AFR22′ may beobtained by moving the second focus ROI AFR22 by the 2D disparity vectorDV2.

Although FIGS. 5, 6, 7, 8 and 9 illustrate examples in which a focus ROIfor AF is only moved, a movement of a white balance ROI for AWB and amovement of an exposure ROI for AE may be substantially the same as themovement of the focus ROI for AF according to embodiments of theinventive concept.

FIG. 10 illustrates a diagram for describing an example of auto focusingin the image pickup device according to embodiments of the inventiveconcept.

Referring to FIGS. 1, 2 and 10 , the first ISP 300 a may determine thefirst position P1 of the first lens 210 a by performing the first AFbased on the first focus ROI (e.g., AFR11 in FIG. 6 ), and may obtainthe first distance Z between the object 10 and the first camera 200 abased on the first position P1 of the first lens 210 a.

In some embodiments of the inventive concept, the first position P1 ofthe first lens 210 a may be any position between a first minimumposition Pmin1 closest to the first sensor 230 a and a first maximumposition Pmax1 farthest from the first sensor 230 a.

In some embodiments, the first distance Z may be obtained based on afirst lookup table. The first lookup table may include a relationshipbetween all positions on which the first lens 210 a can be located(e.g., from the first minimum position Pmin1 to the first maximumposition Pmax1) and preset distances between the object 10 and the firstcamera 200 a corresponding to all the positions.

The second ISP 300 b may calculate the first disparity information basedon the first distance Z, may move the second focus ROI (e.g., AFR21 inFIG. 6 ) based on the first disparity information, and may determine asecond position P2 of the second lens 210 b by performing the second AFbased on the moved second focus ROI (e.g., AFR21′ in FIG. 7 ) and thefirst position P1 of the first lens 210 a. For example, the firstdisparity information may be calculated based on Equation 1 or Equations2, 3 and 4.

In some embodiments, the second position P2 of the second lens 210 b maybe any position between a second minimum position Pmin2 closest to thesecond sensor 230 b and a second maximum position Pmax2 farthest fromthe second sensor 230 b.

In some embodiments, the second position P2 of the second lens 210 b maybe within a first predetermined range with respect to the first positionP1 of the first lens 210 a. In other words, a difference between thefirst position P1 of the first lens 210 a and the second position P2 ofthe second lens 210 b may be smaller than a first threshold value.

In other embodiments of the inventive concept, it may be difficult todirectly compare the first position P1 of the first lens 210 a with thesecond position P2 of the second lens 210 b. In such an example, thesecond position P2 of the second lens 210 b may be determined bycomparing a first focal length with a second focal length. The firstfocal length may correspond to the first position P1 of the first lens210 a, and the second focal length may correspond to the second positionP2 of the second lens 210 b. For example, the second focal length may bewithin a predetermined range with respect to the first focal length.

FIG. 11 illustrates a diagram for describing an example of auto whitebalancing in the image pickup device according to embodiments of theinventive concept. FIG. 11 illustrates a graph of a uniform chromaticityspace and Planckian locus LCS based on (u,v) chromaticity coordinates.

Referring to FIGS. 1, 2 and 11 , the first ISP 300 a may perform thefirst AWB based on the first white balance ROI, and may convert theresult of the first AWB into the first CCT1.

The second ISP 300 b may calculate the first disparity information basedon the first distance Z, may move the second white balance ROI based onthe first disparity information, and may perform the second AWB based onthe moved second white balance ROI and the first CCT CCT1.

In some embodiments of the inventive concept, a second CCT CCT2corresponding to the result of the second AWB may be within a secondpredetermined range CTR with respect to the first CCT CCT1. In otherwords, a difference between the first CCT CCT1 and the second CCT CCT2may be smaller than a second threshold value.

In some embodiments, the first CCT CCT1 and the second CCT CCT2 may beadjusted such that at least one of the first CCT CCT1 and the second CCTCCT2 is located corresponding to the Planckian locus LCS (e.g., locatedon the Planckian locus LCS).

FIG. 12 illustrates a diagram for describing an example of auto exposingin the image pickup device according to embodiments of the inventiveconcept.

Referring to FIGS. 1, 2 and 12 , the first ISP 300 a may perform thefirst AE based on the first exposure ROI, and may convert the result ofthe first AE into the first EI EI1. The first ISP 300 a may furtherdetermine the first exposure time IT1 of the first shutter 220 a basedon the first AE.

In some embodiments of the inventive concept, the first EI EI1 may beany index between a first minimum index EImin1 and a first maximum indexEImax1.

In some embodiments, the first EI EI1 may be obtained based on a secondlookup table. The second lookup table may include a relationship betweenall illuminance values which can be obtained by the first AE and presetindexes corresponding to all the illuminance values.

The second ISP 300 b may calculate the first disparity information basedon the first distance Z, may move the second exposure ROI based on thefirst disparity information, and may perform the second AE based on themoved second exposure ROI and the first EI EI1. The second ISP 300 b mayfurther determine a second exposure time IT2 of the second shutter 220 bbased on the second AE and the first exposure time IT1 of the firstshutter 220 a.

In some embodiments, a second EI EI2 corresponding to the result of thesecond AE may be any index between a second minimum index EImin2 and asecond maximum index EImax2.

In some embodiments, the second EI EI2 may be within a thirdpredetermined range with respect to the first EI EI1. In other words, adifference between the first EI EI1 and the second EI EI2 may be smallerthan a third threshold value.

In some embodiments, the first EI EI1 and the second EI EI2 may beadjusted such that a ratio of the first EI EI1 to the second EI EI2becomes a predetermined ratio.

Although examples where the first distance Z is obtained by the firstISP 300 a and the first disparity information is calculated by thesecond ISP 300 b are described with reference to FIGS. 1 through 12 ,one of the first and second ISPs 300 a and 300 b may perform bothoperations of obtaining the first distance Z and calculating the firstdisparity information according to other embodiments of the inventiveconcept.

FIG. 13 illustrates a block diagram of an image pickup device accordingto embodiments of the inventive concept.

Referring to FIG. 13 , an image pickup device 100 a includes firstthrough n-th cameras 200 a, 200 b, . . . , 200 n (i.e., first and secondthrough nth cameras) and first through n-th ISPs 300 a, 300 b, . . . ,300 n (i.e., first and second through nth ISPs), where n is a naturalnumber equal to or greater than three.

The image pickup device 100 a of FIG. 13 may be substantially the sameas the image pickup device 100 of FIG. 1 , except that the image pickupdevice 100 a of FIG. 13 includes more than two cameras 200 a˜200 n andmore than two ISPs 300 a˜300 n.

The first through n-th cameras 200 a˜200 n obtain first through n-thimages (i.e., first and second through nth images) of an object 10. Forexample, the first camera 200 a may be set as a master camera, and thesecond through n-th cameras 200 b˜200 n may be set as slave cameras.

The plurality of cameras 200 a˜200 n may be disposed or arranged in oneof various forms. In some embodiments of the inventive concept, theplurality of cameras 200 a˜200 n may be disposed on the same surface ofan electronic system (e.g., on a front or back surface of a smart phone)including the image pickup device 100 a. In other embodiments, theplurality of cameras 200 a˜200 n may be disposed in an array or matrixform (e.g., arranged in parallel with each other in one direction or intwo directions). In still other embodiments, the plurality of cameras200 a˜200 n may be disposed in a circular form with respect to theobject 10.

The first ISP 300 a performs a first 3A (e.g., a first AF, a first AWBand the first AE) for the first camera 200 a based on a first ROI in thefirst image. In addition, a first distance between the object 10 and thefirst camera 200 a is obtained based on a result of the first AF, andfirst through (n−1)-th disparity information associated with the firstthrough n-th images are calculated based on the first distance. Thefirst disparity information is associated with the first and secondimages, the second disparity information is associated with the firstand third images, and the (n−1)-th disparity information is associatedwith the first and n-th images.

The second ISP 300 b moves a second ROI in the second image based on thefirst disparity information associated with the first and second images,and performs a second 3A (e.g., a second AF, a second AWB and a secondAE) for the second camera 200 b based on the moved second ROI. The n-thISP 300 n moves an n-th ROI in the n-th image based on the (n−1)-thdisparity information associated with the first and n-th images, andperforms an n-th 3A (e.g., an n-th AF, an n-th AWB and an n-th AE) forthe n-th camera 200 b based on the moved n-th ROI. The 3A for allcameras 200 a˜200 n may be synchronized with each other based on aresult of the 3A for the master camera (e.g., the first camera 200 a).

In some embodiments of the inventive concept, configurations andoperations of the first and second cameras 200 a and 200 b and the firstand second ISPs 300 a and 300 b may be substantially the same as theexamples described with reference to FIGS. 2 through 12 . Cameras (e.g.,the n-th camera 200 n) other than the first and second cameras 200 a and200 b may be substantially the same as the second camera 200 b, and ISPs(e.g., the n-th ISP 300 n) other than the first and second ISPs 300 aand 300 b may be substantially the same as the second ISP 300 b.

In some embodiments, at least a part of the ISPs 300 a˜300 n in FIGS. 1and 13 may be implemented as hardware. In other embodiments, at least apart of the ISPs 300 a˜300 n in FIGS. 1 and 13 may be implemented asinstructions or program routines (e.g., a software program) that areexecuted by a processor and are stored in a storage.

In some embodiments, the ISPs 300 a˜300 n in FIGS. 1 and 13 may beimplemented as separate chipsets or separate integrated circuits. Inother embodiments, at least two of the ISPs 300 a˜300 n in FIGS. 1 and13 may be implemented as one chipset.

Although embodiments where the first camera 200 a is set as a mastercamera are described with reference to FIGS. 1 through 13 , the mastercamera may be changed based on a user setting signal and/or an internalparameter according to other embodiments of the inventive concept.

FIG. 14 illustrates a flow chart of a method of operating an imagepickup device according to embodiments of the inventive concept.

Referring to FIGS. 1, 2 and 14 , in a method of operating the imagepickup device 100 according to embodiments of the inventive concept, afirst AF, a first AWB and a first AE for the first camera 200 a areperformed based on a first ROI in the first image IIMG1 (step S100). Thefirst image IIMG1 is an image of the object 10 and is obtained by thefirst camera 200 a.

The first distance Z between the object 10 and the first camera 200 a isobtained based on a result of the first AF (step S200). First disparityinformation is calculated based on the first distance Z (step S300). Thefirst disparity information is associated with the first and secondimages IIMG1 and IIMG2. For example, the first disparity information mayrepresent differences between the first and second images IIMG1 andIIMG2 that are caused by different points of view of the cameras 200 aand 200 b.

A second ROI in the second image IIMG2 is moved based on the firstdisparity information (step S400). A second AF, a second AWB and asecond AE for the second camera 200 b are performed based on the movedsecond ROI (step S500).

As described with reference to FIGS. 1 and 2 , step S100 may beperformed by the first ISP 300 a, and steps S400 and S500 may beperformed by the second ISP 300 b. Although in some embodiments of theinventive concept step S200 is performed by the first ISP 300 a and stepS300 is performed by the second ISP 300 b, in other embodiments bothsteps S200 and S300 may be performed by one of the first and second ISPs300 a and 300 b.

FIG. 15 illustrates a flow chart of an example of step S100 in FIG. 14 .Step S100 may be performed by first ISP 300 a.

Referring to FIGS. 1, 2, 14 and 15 , in the step of performing a first3A including the first AF, the first AWB and the first AE (step S100), aposition of the first lens 210 a may be determined by performing thefirst AF based on a first focus ROI included in the first ROI (stepS110). In step S200 in FIG. 14 , the first distance Z may be obtainedbased on the position of the first lens 210 a.

Returning to FIG. 15 , the first AWB may be performed based on a firstwhite balance ROI included in the first ROI to convert a result of thefirst AWB into the first CCT CCT1 (step S120). The first AE may beperformed based on a first exposure ROI included in the first ROI toconvert a result of the first AE into the first EI EI1 (step S130).

An exposure time of the first shutter 220 a may be determined based onthe first AE (step S140).

FIG. 16 illustrates a flow chart of an example of step S500 in FIG. 15 .Step S500 may be performed by second ISP 300 b.

Referring to FIGS. 1, 2, 14 and 16 , in step S400 before step S500, asecond focus ROI, a second white balance ROI and a second exposure ROIincluded in the second ROI may be moved based on the first disparityinformation.

Returning to FIG. 16 , in the step of performing a second 3A includingthe second AF, the second AWB and the second AE (step S500), a positionof the second lens 210 b may be determined by performing the second AFbased on the moved second focus ROI and the position of the first lens210 a (step S510). For example, a difference between the position of thefirst lens 210 a and the position of the second lens 210 b may besmaller than a first threshold value.

The second AWB may be performed based on the moved second white balanceROI and the first CCT CCT1 (step S520). For example, a differencebetween the first CCT CCT1 and a second CCT corresponding to a result ofthe second AWB may be smaller than a second threshold value.

The second AE may be performed based on the moved second exposure ROIand the first EI EI1 (step S530). For example, a difference between thefirst EI EI1 and a second EI corresponding to a result of the second AEmay be smaller than a third threshold value.

An exposure time of the second shutter 220 b may be determined based onthe second AE and the exposure time of the first shutter 220 a (stepS540).

As will be appreciated by those skilled in the art, the presentdisclosure may be embodied as a system, method, computer programproduct, and/or a computer program product embodied in one or morecomputer readable medium(s) having computer readable program codeembodied thereon. The computer readable program code may be provided toa processor of a general purpose computer, special purpose computer, orother programmable data processing apparatus. The computer readablemedium may be a computer readable signal medium or a computer readablestorage medium. The computer readable storage medium may be any tangiblemedium that can contain, or store a program for use by or in connectionwith an instruction execution system, apparatus, or device. For example,the computer readable medium may be a non-transitory computer readablemedium.

FIG. 17 illustrates a block diagram of an electronic system according toembodiments of the inventive concept.

Referring to FIG. 17 , an electronic system 1000 includes a processor1010 and an image pickup device 100. The electronic system 1000 mayfurther include a connectivity module or device 1020, a storage device1030, a user interface 1050 and a power supply 1060.

The processor 1010 controls overall operations of the electronic system1000. The image pickup device 100 includes a plurality of cameras C1 . .. , CN and a plurality of ISPs I1, . . . , IN, and may be implementedaccording to the various embodiments described with respect to FIGS.1-16 . In the image pickup device 100, AF, AWB and AE for a mastercamera may be performed based on ROI in an image taken by the mastercamera, AFs, AWBs and AEs for slave cameras may be performed based onROIs in images taken by the slave cameras that are moved by results ofthe AF, AWB and AE for the master camera, and thus the AFs, AWBs and AEsfor all cameras may be synchronized with each other based on the resultof the AF, AWB and AE for the master camera.

In some embodiments of the inventive concept, the processor 1010 maygenerate a composite image by combining images (e.g., OIMG1′ and OIMG2′in FIG. 2 ) that are obtained after the AFs, AWBs and AEs for allcameras are completed. In some embodiments, at least one of the ISPs I1,. . . , IN may be included in the processor 1010.

The connectivity module 1020 may communicate with an external device(not shown). The storage device 1030 may operate as a data storage fordata processed by the processor 1010 or a working memory in theelectronic system 1000. The user interface 1050 may include at least oneinput device such as, for example, a keypad, a button, a microphone, atouch screen, or the like, and/or at least one output device such as,for example, a speaker, a display device, or the like. The power supply1060 may provide power to the electronic system 1000.

The embodiments of the inventive concept may be applied to variousdevices and systems that include an image pickup device having aplurality of cameras. For example, the embodiments of the inventiveconcept may be applied to systems such as be mobile phones, smartphones, tablet computers, laptop computers, personal digital assistants(PDAs), portable multimedia players (PMPs), digital cameras, portablegame consoles, wearable systems, internet of things (IoT) systems,three-dimensional (3D) geometry reconstruction systems, array camerasystems, virtual reality (VR) systems, augmented reality (AR) systems,or the like.

The foregoing is illustrative of example embodiments and should not beconstrued as limiting thereof. Although a few example embodiments havebeen described, those skilled in the art will readily appreciate thatmany modifications of the embodiments are possible without materiallydeparting from the novel teachings and advantages of the presentdisclosure. Accordingly, all such modifications are intended to beincluded within the scope of the present disclosure as defined in theclaims. Therefore, it is to be understood that the foregoing isillustrative of various example embodiments and is not to be construedas limited to the specific example embodiments disclosed, and thatmodifications of the disclosed example embodiments, as well as otherexample embodiments, are intended to be included within the scope of theappended claims.

What is claimed is:
 1. A processor configured to interface with at least two cameras, comprising: a first image processor configured to receive a first image data from a first camera of the at least two cameras, to set a first region-of-interest (ROI) in the received first image data and to perform a first auto-exposure for the first camera based on the first ROI and transfer a first exposure index; and a second image processor configured to receive a second image data from a second camera of the at least two cameras, to set a second ROI in the received second image data, to move the second ROI in the received second image data based on disparity information between the received first image data and the received second image data, and to perform a second auto-exposure for the second camera based on the moved second ROI and the first exposure index.
 2. The processor of claim 1, wherein the first camera is a master camera and the second camera is a slave camera, and wherein determination of the first camera and the second camera as the master camera and the slave camera is based on a user setting signal or an internal parameter.
 3. The processor of claim 2, wherein the disparity information is calculated based on a distance between an object and the master camera.
 4. The processor of claim 3, wherein the distance between the object and the master camera is determined by a first auto-focusing operation of the first camera based on the first ROI.
 5. The processor of claim 4, wherein the disparity information is calculated further based on a baseline between the first camera and the second camera.
 6. The processor of claim 1, wherein a location of the moved second ROI in the second image data is shifted by the disparity information from a location of the first ROI in the first image data.
 7. The processor of claim 1, wherein the second image processor is configured to generate a second exposure index based on performance of the second auto-exposure and the second exposure index is within a predetermined range with respect to the first exposure index.
 8. The processor of claim 7, wherein a difference between the first exposure index and the second exposure index is smaller than a threshold value.
 9. The processor of claim 1, wherein the processor further comprises a storage memory storing a lookup table about a relationship between illuminance values and preset indexes relating to the first exposure index.
 10. The processor of claim 4, wherein the second image processor is further configured to perform a second auto-focusing operation based on the moved second ROI and the disparity information.
 11. The processor of claim 5, wherein the first ROI and the second ROI are set based on predetermined rules or criterions and when the processor is operated for video conferencing applications, the first ROI and the second ROI include a face of the object.
 12. A processor configured to interface with at least two cameras, comprising: a first image processor configured to receive a first image data from a master camera of the at least two cameras, to set a first region-of-interest (ROI) in the received first image data and to perform a first auto-white balance for the master camera based on the first ROI and generate a first correlated color temperature; and a second image processor configured to receive a second image data from a slave camera of the at least two cameras, to generate a second ROI in the received second image data based on disparity information between the received first image data and the received second image data, and to perform a second auto-white balance for the slave camera based on the generated second ROI and the first correlated color temperature.
 13. The processor of claim 12, wherein the disparity information is calculated based on a distance between an object and the master camera.
 14. The processor of claim 13, wherein the distance between the object and the master camera is determined by a first auto-focusing operation of the master camera based on the first ROI.
 15. The processor of claim 14, wherein the disparity information is calculated further based on a baseline between the master camera and the slave camera.
 16. The processor of claim 12, wherein a location of the generated second ROI in the second image data is shifted by the disparity information from a location of the first ROI in the first image data.
 17. The processor of claim 12, wherein the second image processor is configured to generate a second correlated color temperature based on performance of the second auto-white balance and the second correlated color temperature is within a predetermined range with respect to the first correlated color temperature.
 18. The processor of claim 17, wherein a difference between the first correlated color temperature and the second correlated color temperature is smaller than a threshold value.
 19. The processor of claim 18, wherein the first correlated color temperature and the second correlated color temperature is located corresponding to Planckian locus.
 20. An electronic system comprising: a first camera comprising a first complementary metal oxide semiconductor (CMOS) image sensor; a second camera comprising a second CMOS image sensor and arranged in parallel with the first camera in a first direction; and a processor configured to control the first and second cameras, wherein the processor comprises a first image processor configured to receive a first image data from the first camera, to set a first region-of-interest (ROI) in the received first image data and to perform a first auto-exposure for the first camera based on the first ROI and transfer a first exposure index, and a second image processor configured to receive a second image data from the second camera, to set a second ROI in the received second image data, to move the second ROI in the received second image data based on disparity information between the received first image data and the received second image data, and to perform a second auto-exposure for the second camera based on the moved second ROI and the first exposure index. 